FeSiAl-based soft magnetic composites (SMCs), prepared from insulated FeSiAl powders, are widely applied in electronic devices. However, it is still challenging to achieve high magnetic and mechanical properties simultaneously due to the undesirable insulation layer. Here, double Al2O3 insulation layers are prepared for FeSiAl SMC. Atomic-scale characterizations reveal an in-situ epitaxial Al2O3 layer at FeSiAl surface under the catalysis of NaAlO2, and an outer amorphous Al2O3 layer by subsequent NaAlO2 hydrolysis. The above structure ensures effective insulation of FeSiAl powders and excellent magnetic properties of the FeSiAl/NaAlO2 SMC, with permeability of 101 and power loss of 128 mW/cm3 (50 mT, 100 kHz) respectively. Moreover, in-situ Al2O3/amorphous Al2O3 on FeSiAl matrix also leads to distinguished crush strength of 36.5 MPa for the core sample, which is ascribed to the enhanced adhesion at different interfaces as evidenced by similar local oxygen coordination and low strain distribution. This work provides a novel method to fabricate high-performance FeSiAl SMCs.

中文翻译：

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FeSiAl 软磁复合材料具有双 Al2O3 绝缘层，可同时实现高机械和磁性


由绝缘 FeSiAl 粉末制备的 FeSiAl 基软磁复合材料 （SMC） 广泛应用于电子器件。然而，由于不需要的绝缘层，同时实现高磁性和机械性能仍然具有挑战性。在这里，为 FeSiAl SMC 准备了双 Al2O3 绝缘层。原子级表征揭示了在 NaAlO2 催化下 FeSiAl 表面的原位外延 Al2O3 层，以及随后的 NaAlO2 水解的外部无定形 Al2O3 层。上述结构确保了 FeSiAl 粉末的有效绝缘和 FeSiAl/NaAlO2 SMC 的优异磁性能，磁导率分别为 101 和功率损耗 128 mW/cm3（50 mT，100 kHz）。此外，FeSiAl 基体上的原位 Al2O3/非晶态 Al2O3 也导致岩心样品的抗压强度达到 36.5 MPa，这归因于在不同界面处的粘附力增强，相似的局部氧配位和低应变分布证明了这一点。这项工作提供了一种制备高性能 FeSiAl SMC 的新方法。